If my daughter dies before me what happens to the life estate I made?

I will assume that you conveyed your real property to your daughter and reserved a life estate in that property. In that case, your daughter is the owner of the property. She can leave it to someone in her will or it will pass to her heirs-at-law under the laws of intestacy in your state. Generally, if she is married with children, her husband and children will inherit the property if she has no will. You can check your state laws of intestacy at the related question link provided below. Your daughter's death will not affect your life estate. Whoever would inherit her property upon her death either by will or by intestacy would inherit it subject to your life estate.